1. Technical Field
The present invention generally relates to a driving apparatus, and more particularly to a driving apparatus that could achieve an adjustable driving current output.
2. Description of Related Art
Electronic loads have two types of driving modes, one is current driving mode and the other one is voltage driving mode. For different electronic loads, such as electrical motors, light emitting diodes (LEDs), liquid crystal displays (LCDs), etc., stable and adjustable driving voltages/currents circuits are needed.
Referring to FIG. 8, a driving apparatus 100 configured for supplying a driving current to a target load 101 is provided. The driving apparatus 100 includes a rectifier 110, a micro-programmed control unit (MCU) 120, a digital input driving circuit 130, and an output circuit 140. The rectifier 110 converts a high voltage alternating current (AC) voltage Vac to a high voltage direct current (DC) voltage Vdc. The high voltage DC voltage Vdc can be used as power supply to the digital input driving circuit 130 and the target load 101. A DC voltage Vdc1 as a power source to the MCU 120. The MCU 120 generates/produces a pulse width modulation (PWM) signal. The digital input driving circuit 130 modulates the PWM signal to generate an output signal Vg. The output circuit 140 receives the output signal Vg and then generates a driving current Ic with a level in conjunction with that of the output signal Vg. Finally, the driving current Ic generated by the output circuit 140 can be inputted into the target load 101 for driving the target load 101. Even further, the digital input driving circuit 130 could also generate a stable and constant driving voltage Vout used to drive other loads.
However, because the PWM signal is controlled by embedded software or firmware and is generally preprogrammed by the manufacturer, the PWM signal is non-adjustable, so the output signal Vg cannot be varied correspondingly, which results in electrical parameters of the driving current Ic generated by the driving apparatus 100 could not be adjusted. As such, the above-mentioned driving apparatus 100 is difficult to meet the different driving currents requirements for different target loads.
What is needed, therefore, is a driving apparatus could achieve an adjustable driving current output.